TAMPA -- A flatbed tractor trailer carrying bags of ready-mix concrete crashed on a Selmon Expressway overpass Tuesday, forcing authorities to close the westbound side of the highway near downtown for hours.

The crash happened around 8:30 a.m., and one westbound lane was reopened at 1 p.m. The other lane was expected to open later today, likely around 4 p.m., Florida Department of Transportation officials said.

According to the Florida Highway Patrol, Mark Owen Pickard, 45, of Seffner was driving the Freightliner west toward the downtown Tampa exit. Troopers said he failed to maintain control of the truck and collided with the guardrail crash attenuator located at the apex of the exit ramp.

After the impact, the truck continued up and onto the outside barrier wall and traveled 600 feet along the top of the wall, troopers said. The truck also collided with three light poles that were fixed to the wall before coming to rest at a 45 degree angle, with its right-side wheels over and on top of the wall.

Portions of load spilled onto the roadway.

During the time both westbound lanes were closed, westbound traffic was detoured onto Adamo Drive (State Road 60).